Wetting is a property of a liquid/solid interface governed by adhesive forces between the liquid and solid and cohesive forces in the liquid. Adhesive forces between the liquid and solid cause the liquid to spread across the solid surface. Cohesive forces in the liquid cause the liquid to minimize contact with the solid surface. The wetting of a solid surface by a liquid is important in many industrial processes where a liquid interacts with a solid surface. Electroplating (a cathodic process), including electroplating in integrated circuit manufacturing, is one such industrial process. Wetting is also important in anodic processes, including electroetching and electropolishing.
For example, many semiconductor and microelectronic processes make use of through resist electrodeposition. This plating process is also sometimes referred to as through-mask or photoresist patterned electrodeposition. These processes may be associated with plating submicrometer gold interconnects on GaAs wafers, plating copper coils or magnetic alloys for thin-film recording heads, plating copper conductors for redistribution or integrated passive applications, or plating PbSn or lead-free solders for flip chip connection. All of these processes involve substrates having a blanket conductive seed layer, or a conductive plating base, and a patterned dielectric template, into which metal is deposited.